Dishwasher appliances generally include a tub that defines a wash chamber. Rack assemblies can be mounted within the wash chamber of the tub for receipt of articles for washing. During wash and rinse cycles, spray assemblies within the wash chamber can apply or direct wash fluid (e.g. various combinations of water and detergent along with optional additives) towards articles disposed within the rack assemblies in order to clean such articles.
To improve spray coverage, multiple spray assemblies can be provided including e.g., a lower spray arm assembly mounted to the tub at a bottom of the wash chamber, a mid-level spray arm assembly mounted to one of the rack assemblies, and/or an upper spray assembly mounted to the tub at a top of the wash chamber. Other configurations may be used as well.
One limitation of many currently known spray arm assemblies is the geometry of the spray arm assemblies and their fixed nozzle positions and orientations. For example, rotating spray arms typically have multiple nozzles positioned along a length of the spray arm. As the spray arm rotates, each nozzle emits wash fluid from a fixed location relative to the arm and in a fixed direction, generating a predictable and limited circular spray pattern having gaps in spray coverage. These limitations can result in articles not being properly cleaned during operation of the dishwasher appliance.
Spray coverage gaps can be decreased by using more nozzles or by shaping the nozzles as slots to generate a broader spray from each nozzle. However, such nozzle adjustments will result in decreased impingement force unless the hydraulic power is increased. Increasing the hydraulic power results in noisier operation and increased energy consumption. Moreover, increasing the number of nozzles or the spray coverage area of the nozzles increases overall energy and water consumption.
Accordingly, improved spray assemblies and associated dishwasher appliances are desired in the art. More specifically, improved spray assembly designs which increase the coverage of the wash fluid while reducing the noise and energy consumption of a dishwasher appliance would be particularly beneficial.